San Diego State University will build the largest research telescope in school history, a 50-inch instrument that will examine distant objects that vary in brightness, revealing clues about the physical nature of the universe.

The $1.7 million Phillips Claud Telescope will replace SDSU's original 16-inch research telescope, and enable the school to analyze objects spotted during deep sky surveys conducted by other institutions.

The new remotely-controlled instrument has computers and optics that will make it far more powerful than a 40-inch telescope that San Diego State operates at the Mount Laguna Observatory, 45 miles east of the city. But it doesn't compare to the famed 200-inch Hale Telescope at Palomar Observatory, in north county.

"There are a number of dedicated survey telescopes that are coming online, such as PanStarrs and the LSST, but most large telescopes are not routinely used for surveys," said Allen Shafter, chair of astronomy at San Diego State.

"The major advantage of our new telescope is that ... (we) will be able to obtain large blocks of observing time not readily available at other facilities to do detailed follow-up work in variable objects discovered by the dedicated sky surveys."

The $1.7 million project is being funded with public and private money, nearly half of which comes from the estate of Phillips Claud, an amateur astronomer who was close to members of the university's astronomy department. The university also had other major donors, including the Brenda and Dave Rickey Foundation, which donated $100,000. The school also got about $98,000 in royalties from work by SDSU's spin-off company, Astronomical Research Cameras, Inc.

The university will focus on so-called variable objects, which range from stars whose brightness changes periodically to stars with sudden, violent eruptions, to exo-planets (worlds beyond our solar system) whose presence is sometimes revealed by the movement of stars.

Michael Bakich, a senior editor at Astronomy magazine, said, "Every new telescope that comes online adds to our knowledge, and San Diego State is carving out its own niche. They're not just duplicating someone else's work."

The Claud Telescope is expected to come online in late 2011, almost a decade after the project began. SDSU, Kansas and a private company used public and private money to experiment with carbon-fiber reinforced plastic mirrors. "The project to test the novel plastic mirrors ended in the summer of 2008, thus freeing up the telescope mount and dome for the new Claud Telescope," said Paul Eztel, director of the Mount Laguna Observatory.

SDSU decided to use a conventional mirror for the telescope, and the university has recently obtained enough money to project -- progress largely made possible by private donations.

"The funding of the new MLO telescope is one bright spot in the otherwise dismal funding situation for higher education in California," Shafter said.